Field
The present disclosure generally relates to manual resuscitation devices and, in particular, a resuscitator that incorporates electronic sensing and processing.
Description of the Related Art
A resuscitator, sometimes referred to as a bag valve mask (BVM) or by the proprietary name “Ambu bag,” is a hand-held device used to provide positive pressure ventilation to a patient who is not breathing or who is breathing inadequately. The resuscitator is a normal part of a “crash cart” used within a hospital or a resuscitation kit provided to ambulance crew. A resuscitator may also be used in an operating room to ventilate an anaesthetized patient prior to attachment of a mechanical ventilator. A resuscitator may be self-filling with air or provided with a source of breathing gas, such as oxygen, to increase the oxygenation of the patient.
FIG. 1 depicts a conventional resuscitator 10 that is connected to a line 20 that provides oxygen or other breathing gas. A bag 14 is connected to a mask 12 by a flow channel 16 that also has a valve assembly 18 that prevents backflow into the bag 14 and diverts exhaled gas to the atmosphere. An accumulator bag 22 is connected at the junction of the bag 14 and line 20 to accumulate a reservoir of oxygen such that the self-expansion of the bag 14 is not limited by the flow rate of line 20.
When using a resuscitator, there is a risk of over-inflating the lungs. This can lead to pressure damage to the lungs themselves and can also cause air to enter the stomach, causing gastric distension which can make it more difficult to inflate the lungs. Over-inflation may also cause the patient to vomit, which can cause additional airway problems beyond the original breathing difficulty.
FIG. 2 depicts another conventional resuscitator 30 having a mechanical pressure gauge 32 connected to the flow channel 16. The gauge 32 is marked with a green zone to indicate the desirable range of inflation pressure as well as yellow and red zones to indicate zones of excess inflation pressures. These types of mechanical gauges have limited resolution and reading such a gauge can be a challenge for caregivers as the gauge provides only an instantaneous reading and the caregiver cannot pay constant attention to the gauge as they may be performing other actions, for example striving to maintain a proper seal of the mask to the patient's face and monitoring other symptoms and aspects of the patient's condition.